The present invention relates to an electric control circuit for a safety apparatus adapted to be actuated by an electrically operated actuator, and more particularly to an electric control circuit in which an electric power source in the form of a vehicle battery is connected through a normally open switch with the actuator to supply electric energy to the actuator when the switch is closed in the occurrence of a vehicle collision.
In such an electric control circuit as noted above, the vehicle battery is assembled within an engine room compartment, and the switch is mounted on the front bumper of the vehicle or a central portion of the vehicle chassis. Meanwhile, the actuator is housed within the safety apparatus located in the passenger compartment. In the electric wiring of the control circuit, a number of conductors leading from the vehicle battery are connected at a long distance with the switch and actuator. If the conductors are disconnected or shorted with another conductor, the actuator may not be supplied with electric energy from the battery in the occurrence of a vehicle collision, and the safety apparatus then remains inoperative. This means that various shorts or disconnections of the conductors must be detected prior to the occurrence of a vehicle collision.